Optimization of Ultrasound-Assisted Extraction of Anti-Glycation Agents from Ecklonia cava

Ultrasound-assisted extraction conditions were optimized to improve the extraction of advanced glycation end products (AGEs) inhibitors from Ecklonia cava extracts using response surface methodology. Conditions considered were extraction temperature (30–70°C), ethanol concentration (20–100%), and extraction time (10–50 min). Dependent variables were dieckol content, yield, and degree of AGEs inhibition measured in three anti-glycation assay models; namely, bovine serum albumin (BSA)-fructose (Fru), BSA-methylglyoxal (MGO), and BSA-glyoxal (GO). Overall, dieckol content increased, but AGEs formation and yield decreased, with increasing ethanol concentration. In the BSA-MGO model, AGEs inhibition decreased with increasing extraction temperature. The four-dimensional graphs were superimposed to select optimum conditions. The optimum conditions were determined as 50–60°C of extraction temperature, 70%–85% of ethanol concentration, and 25–35 min of extraction time. The suitability of the prediction model was evaluated by comparing the actual and predicted values of responses, and the results confirmed that our prediction model is suitable. IC₅₀ of Ecklonia cava extract against BSA-Fru, BSA-MGO, and BSA-GO was 0.44, 0.56, and 0.73 mg/mL, respectively. The AGEs inhibition effect of Ecklonia cava extract in the BSA-MGO model was better than that of aminoguanidine at the same concentration.